The present invention relates generally to switches and more particularly to a switch integral to a latch assembly.
Electronic assemblies may be configured and assembled in such a manner that one or more printed circuit assemblies (PCA) are housed in a single chassis. Individual PCAs may be mounted in structural modules for insertion into the chassis. Alternately, the PCA may be fabricated including an edge configured for sliding engagement with the electronic assembly chassis. Each PCA includes one or more connectors for conductively connecting the PCA to other electrical or electronic equipment or components forming the electronic assembly. Each PCA commonly includes a first connector portion which engages with a second connector portion inside the chassis, most commonly located on an end plate.
Each PCA may include an insert/extract latch assembly which facilitates insertion of the PCA into and extraction of the PCA from the chassis. A latch is connected to the PCA or the structural module of the PCA and is employed to apply leverage against the structural module to effect complete insertion of the PCA into the chassis and engagement of the connectors. The chassis may include a lip or frame surrounding an aperture in the faceplate of the electronic assembly housing through which the PCA is insertable. A retainer is employed to eliminate any tendency of the latch to become disengaged inadvertently. The insert/extract latch assembly facilitates engaging and disengaging the connector component parts when inserting and removing the PCA from the chassis.
Accidental removals of PCAs from the chassis can occur which may result in adverse effects on system operation. It may therefore be advantageous to provide an insert/extract latch assembly which include an early removal warning switch.
The present invention is directed to a switch integral to an insert/extract latch assembly. The switch is positioned between a latch and a retainer and may be compressed between the latch and the retainer. The retainer is movable between first and second positions. In the first position, the retainer is selectively disengaged from the latch, the switch contacts are open and the latch is free to operate. In the second position, the retainer is selectively engaged with the latch, the switch is engaged between the latch and the retainer and the switch contacts are closed.
An insert/extract latch release warning assembly, according to the present invention, includes an insert/extract latch assembly attached to an electronic assembly configured to exert an insert/extract force between the PCA or the structural module of the PCA and the chassis. The insert/extract latch release warning assembly also includes a switch integral to an insert/extract latch assembly for operating a warning circuit for the electronic assembly. The switch is conductively connected to a warning circuit which may operate to deenergize the electronic assembly upon disengagement of the latch from the retainer.
The retainer may be configured as a biased member and is configured to exert a compressive force against the latch. In a first position, the biased member may be depressed away from the latch releasing the latch for operation. In a second position, the biased member returns to a normal position retaining the latch and compressing the switch disposed between the latch and the biased member.
Alternately, the retainer may be configured as a rotatable member connected to the PCA and rotatable about an axis. The rotatable member may be twisted or rotated to a first position wherein the latch is operable. In a second position, the rotatable member is twisted or rotated so that the head of the retainer extends over a portion of the latch retaining the latch and compressing the switch disposed between the latch and the biased member.
In one embodiment of the invention, the switch is integral to the retainer. Alternate embodiments of the invention are possible wherein the switch is integral to the latch. The switch may be configured as a micro switch physically connected to the retainer, conductively connected to a warning circuit and engageable between the latch and the retainer. Alternately, the switch may be configured as a capacitive sensor, a photo-interrupter device, a hall device or switching may be achieved by existing position sensing technologies.